Ship construction



Feb. 20, 1940. H. P. FREAR SHIP CONSTRUCTION Original Filed July 19,1934 4 Sheets-Sheet 1 M H We Feb. 20, 1940. H. P. FREAR SHIPCONSTRUCTION Original Filed July 19, 1934 4 Sheets-Sheet 2 Feb. 20,1940. H; P. FREAR SHIP CONSTRUCTION Original Filed July 19, 1934 Feb.20, 1910. H. P. FREAR sxm coNs'rnUcTIoN 4 Sheets-Sheet 4 Original FiledJuly 19, 1934 Qwuentoz Reiesued Feb. 20. 1940 UNITED STATES PATENTOFFICE SHIP CONSTRUCTION Hugo P. Frear, New York, N. Y., assignor, by

mesne assignments, to Bethlehem Steel Company, a corporation ofPennsylvania Claims.

This invention relates to improvements in the structure of floatingvessels or ships of all types, but especially to vessels designed tocarry liquid cargo in bulk, commonly called tankers, and built 5 on thequasi longitudinal system of framing.

The present application is a re-issue application of my Patent No.2,103,715, Serial No. 59,211, filed January 15, 1936, which was acontinuationin-part of my then co-pending application, Serial No.688,574, flied September 8, 1933, which issued as Patent No. 2,053,903,and was a divisional application of my then co-pending application,Serial No. 735,923, filed July 19, 1934, which issued as Patent No.2,053,904. In another appli- 5 cation (Serial No. 59,212, Patent No.2,071,925)

filed concurrently with my application, Serial No. 59,211, I havedisclosed and claimed broadly the feature of maintaining continuity ofstrength of iongitudinals where out by the bulkheads and this presentapplication discloses and claims a specific form thereof.

The chief object of the present invention is to provide improved meansfor maintaining continuity of strength in the longitudinals of theship's framing where cut by the bulkheads.

Another object of the present invention is to provide continuity ofstrength in the longitudinals of the ship's framing where cut by thebulkheads by welding additional metal to connect the ends of thelongitudinals where cut by the bulkheads and to have this additionalmetal of a preferred shape as will hereinafter be described and setforth.

Another object of the present invention is to 5 reduce to normal theunit stresses developed in theships plating at'the line of thetransverse bulkheads.

Another object of the present invention is to make a considerable savingin the weight 01' 40 the framing of the ship over the usual framing withits initial saving in cost and future savings due to added capacity andreduced tolls.

With these objects in view, the present invention, broadly stated,resides in a ship or the like, particularly for carrying liquid cargo inbulk, in which longitudinal stiifeners are cut at a transverse bulkhead,and in which strength is restored to the stifieners across the bulkheadat the outer portions of the stiifeners by plates having edges welded tothe stifieners and other edges welded to the bulkhead or to boundarybars associated therewith and at the inner portions of said stiflenersby a round bar extending watertight through the bulkhead by reason ofbeing welded thereto and welded to the ends of the stifleners.

By using a round bar at this point I have found that itcombines with ahigh eiliciency inincreasing the section modulus a particular adapta- 5bility to its being welded to the longitudinals, by reason of theangles, formed when in contact with the longitudinals which angles areideal for receiving the weld metal, and by reason of its convenientapproach for welding. Furthermore 10 the round section requires only thesimplest form of piercing of the bulkhead platingthat of a round holewhich may be formed either by means of the welding torch, or arc; or bythe more conventional means of drilling or punching.

The novel features will be more fully understood from the followingdescription and claims taken with the drawings, in which:

Fig. 1 is a partial section through a vessel lllustrating one form ofcontinuing the strength 20 of longitudinals through the bulkheads;

Fig. 2 is a cross-section taken along the line 2-2 of Fig. 1;

Fig. 3 is a cross-section taken along the line 3-3 of Fig. 1;

Fig. 4 is a similar view to Fig. 1 illustrating a modification in thebulkhead;

Fig. 5 is a cross-section taken along theline 55 of Fig. '7;

Fig. 6 is a cross-section taken along the line 30 6-6 of Fig. 5;

Fig. 7 is a view taken on the line ll of Fig. 5;

Fig. 8 is a cross-section taken along the line 88 of Fig. 10illustrating a further modlflcation;

Fig. 9 is a cross-section taken along the line 9-9 of Fig. 8;

Fig. 10 is a view taken on the line Ill-l0 of Fi 8:

Fig. 11 is a diagrammatic layout of a hold plan of a vessel withtransverse and longitudinal bulkheads adapted for longitudinal framingembodying my invention;

Fig. 12 is an enlarged cross-section in part taken on the line l2l2 ofFig. 11 and illustrates the longitudinal framing;

Fig. 13 is a longitudinal section taken horizontally through a portionof the vessel of Fig. 11 and illustrates the embodiment of my inventionto the ship's longitudinals; and

Fig. 14 is a modification of Fig. 4 and embodies my invention in itssimplest form.

Referring now to Figures 1, 2, 3, 11, 12, and 13, the bulkhead platingIII is shown suitably attached to the bulkhead boundary bar H a bywelding H. The longitudinal stifl'eners ll have their outer or platingflanges strengthened and extended in breadth on both sides and towardthe ends by means of the flange extension plates l4 welded as at IE tothe stifl'eners it. As assembled in the finished vessel the extensionplates l4 together with the cut ends of the stifl'eners I3 are welded asat It to the plating flanges ll of the boundary bar H. Member I8 ispreferably a round tie rod passing through the bulkhead plating I0 andwelded or fused to the adjacent ends of the aligned longitudinalstifleners l3. It is also welded watertight to the bulkhead plating II)as at l9.

In Fig. 4 I show a modification to the design shown in Figs. 1, 2, and3. In this modification the boundary bar comprises two angle bars 2|suitably attached to the bulkhead plating and has the heels of the bars2| welded together as at 22, and the horizontal flanges of the bars 2|welded, as at 23, to the flanges of the stifieners l3 in a mannersimilar to that shown in Figs. 1 and 2.

In case it is necessary to provide for drainage through the stifleners,I may do so by means ofthe slots 24 in Figs. 1 and 2. The edges of theslots are securely welded to the ships plating.

The stiifeners l3 are preferably continuously welded to the ship'splating as at 25.

The extension plates l4 may be increased or reduced or be limited to oneside only of the stifieners l3 as the exigencies of interference ofplate or other circumstances in design demand.

By reason of the flange extension plates [4 being welded to thestifieners l3, and both in turn welded to the boundary bar II, thecontinuity of strength at the outer flange of the stifieners I3 ismaintained; and by reason of the tie rod l8 welded or fused to the innerflanges of the stiffeners |3 the continuity of strength at the innerflange is maintained. Furthermore by proper proportioning of theextension plates I4 and the tie rod l8 the continuity of strength in thestiffener through the bulkhead both longitudinally and as a beam may bemaintained. The pull of the aligned stifieners I3 is carried through thebulkhead without cutting the boundary bar H or the passing of doublingsunder the bar, thereby avoiding the objection of increasing the numberof plies for riveting and the difliculty of making and keeping tight.The flanges ll of the boundary bar II is neutral as far as performingany longitudinal work on the plating goes, so that the eflect of joiningthe aligned longitudinal stifieners l3, as described, is to restore theplating to exactly the same condition it would have been in if thestiflfeners had not been cut. Furthermore, as broadly disclosed andclaimed in my application (Serial No. 59,212, Patent No. 2,071,925)filed concurrently with my application (Serial No. 59,211, Patent No.2,103,715), the latter being the original application of the presentre-issue application, by the proper proportioning of the extensionplates l4 and the tie rod I8 I am able to make a considerable saving inweight of longitudinals over prior practice. I make this saving, asdescribed in said application, by so proportioning the extension platesI4 and the tie rod it that the section modulus thereof adjacent thebulkhead plating shall not be less than the sectional modulus of thestiffeners l3 in way of the web members 25. The sectional area of thetie rod l8 and the area of the plating between two adjacent stiflenerends is solely used in calculating the sectional modulus. The length oftie rod It on either side of the bulkheads along the stifleners l3, asdisclosed in the aforesaid application, is such that it is not short ofthe point nearest the bulkhead in the stiifeners l3 where the bendingmoment'of said stiifeners is not less than the bending moment midwaybetween the bulkheads and the nearest web member, or for a distancepreferably not beyond the point of inflection nearest the bulkhead. Thesaid two points being respectively approximately 10% and 21% of thedistance from the bulkhead to the nearest web member. When thus properlycalculated I am enabled to make my stiffeners l3 of the minimum sectionas determined by the stresses midway be tween the supports instead of,as has been the practice heretofore, having the section determined bythe stresses at the supports. The saving in weight is readily seen to bean important feature of my invention.

In Figs. 5, 6, and 7 I show a modification to the design shown in Figs.1, 2,'and 3. In this modification the longitudinal stifleners 21comprise a. web plate 28 continuously welded as at 29 along its outeredge to the ships plating 30 and having welded along its inner edge thereenforcing bar 3|. At the ends of stifleners 21 where cut by thebulkheads 32 (similar to II! of Fig. 1) the outer edge of the web plate28 is coped out to accommodate the flange plate or bracket 33. The copein the web plate 28 is allowed to extend beyond the end of the flangeplate 33 to provide a drain opening 34. The flange plate 33 is welded tothe web plate 28 as at 35 and is welded to the ship's plating 3B and tothe bulkhead 32 as shown at 36 and 31 respectively.

In Figs. 8, 9, and 10 I show another modification to the design shown inFigs. 1, 2, and 3. The bulkhead 3B and the boundary bar 39 may besimilar to that shown in Fig. 1. The longitudinal stiflfeners 4|!comprise an angle bulb beam. The stiffeners 40 are coped at the ends toaccommodate the flange plates 4| in a similar manner as that justdescribed for the stiiIeners 21.

In still another modification, shown in Fig. 14, it is obvious that oneor both of the boundary bars 2| of Fig. 4 could be dispensed with and insuch cases the longitudinal stiifeners 42 would be welded directly tothe bulkhead 43 by the weld metal 44.

In Fig. 11 I have shown diagrammatically a hold plan of a type of vesselparticularly adapted for embodying my invention. The vessel would beconstructed with plating on the bottom 45,

- sides 46, and deck 41, on the quasi longitudinal system of framing,especially designed to carry a liquid cargo in bulk. It would comprisea. plurality of tanks 48 formed by longitudinal bulkheads 49 and closelyspaced transverse bulkheads 50 attached to the ship's plating 46 and tothe longitudinal bulkheads 49. The transverse bulkheads 5|! wouldcomprise the plating HI and the boundary bars ll of Fig. 1. Referringnow to Figs. 12 and 13, the framing of the vessel would compriserelatively deep and widely spaced transverse webs 26 attached to theships plating and to the longitudinal bulkheads. The framing would alsocomprise relatively narrow and closely spaced longitudinal stlffeners5|. The said stiffeners 5| would comprise the members I3 of Fig. 1 orits hereinbefore described modification.

The terms and expressions which I have herein employed are used as termsof description and not or limitation, and I have no intention, in theuse of such terms and expressions, of excluding any equivalents of thefeatures thereof, but recognize that various modifications are possiblewithin the scope oi the invention claimed.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In a vessel of quasi longitudinal construction, transverse bulkheads,fore-and-ai't walls, water-tight means attaching the peripheral edges ofsaid bulkheads to said walls, longitudinal stitfeners comprising innerand outer flanges cut through by said bulkheads in such a manner thatthe cut ends are in proximity to but in spaced relation to saidbulkheads on each side thereof, said outer flanges being attached totheir adlacent one of said walls and at said out ends beingwelded totheir adjacent one of said means, and round tie rods piercing saidbulkheads and welded water-tight and completely around its periphery tosaid bulkheads and welded to said inner flanges of adjacent cut ends ofsaid stiii'eners.

2. In a vessel of quasi longitudinal construction, transverse bulkheads,fore-and-aft walls, water-tight means attaching the peripheral edges ofsaid bulkheads to said walls, longitudinal stilfeners comprising innerand outer flanges cut through by said bulkheads in such a manner thatthe cut ends are in proximity to but in spaced relation to saidbulkheads on each side thereof, and round tie rods piercing saidbulkheads and welded water-tight and completely around its periphery tosaid bulkheads and welded to said inner flanges oi adjacent cut ends ofsaid stiteners.

3. In a vessel, a plate member, a stiiiener comprising an inner chordmember cut throu h by said plate member in such a manner that the cutinner chord member is in proximity to but in spaced relation to saidplate member on each side thereof, and a round tie rod piercing saidplate member and welded water-tight to said plate member and welded tothe cut ends of said inner chord member.

4. In a vessel, a plate member, a stifl'ener comprising inner and outerchord members out through by said bulkhead in such a manner that the cutinner chord member is in proximity to but in spaced relation to saidplate member on each side thereof, and a round tie rod piercing saidplate member and welded water-tight to said plate member and welded tosaid inner chord members of the cut ends oi said stiflener.

5. In a vessel, a bulkhead, fore and aft walls, water-tight meansattaching the peripheral edges of said bulkhead to said walls, astiffener comprising inner and outer chord portions cut through by saidbulkhead in such manner that the cut ends of said chords are inproximity to but in spaced relation to said bulkhead on each sidethereof, said out outer chord portions being attached to their adjacentone of said walls and at said out ends being welded to their adjacentone of said means, and a round tie rod piercing sai'd bulkhead andwelded water-tight around its periphery to said bulkhead and welded tosaid inner chord portions of the cut ends 01' said stiti'ener.

